What if someone's view are so far left that they don't support either Democrats or Republicans? For example, there are a lot of people, especially young people, who believe that we are doomed if we don't make drastic changes to combat climate change. They think that no other issues matter and neither Democrats nor Republicans come close to addressing the issue sufficiently. Why should they "get in line" when there is no party to line up behind? Regardless of what MB thinks, the Democrats are not entitled to those votes. Everybody's vote is their own and no party is entitled to it.